• Title/Summary/Keyword: Transitional Process

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Computational simulations of transitional flows around turbulence stimulators at low speeds

  • Lee, Sang Bong;Seok, Woochan;Rhee, Shin Hyung
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.13 no.1
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    • pp.236-245
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    • 2021
  • In this study, direct numerical and large eddy simulations of transitional flows around studs were conducted to investigate the effectiveness of turbulence stimulators at very low speeds for the minimum propulsion power condition of four knots. For simplicity, the studs were assumed to be installed on a flat plate, while the wake was observed up to 0.23 m downstream behind the second stud. For applicability to a model ship, we also studied the flow characteristics behind the first and second studs installed on a curved plate, which was designed to describe the geometry of a bulbous bow. A laminar-to-turbulent transition was observed in the wake at ReD ≥ 921 (U≥0.290 m/s), and the wall shear stress at ReD = 1162 (U = 0.366 m/s) in the second wake was similar to that of the fully developed turbulent boundary layer after a laminar-to-turbulent transition in the first wake. At ReD = 581 (U = 0.183 m/s), no turbulence was stimulated in the wake behind the first and second studs on the flat plate, while a cluster of vortical structures was observed in the first wake over the curved plate. However, a cluster of vortical structures was revealed to be generated by the reattachment process of the separated shear layer, which was disturbed by the first stud rather than directly initiated by the first stud. It was quite different from a typical process of transition, which was observed at relatively high ReD that the spanwise scope of the turbulent vortical structures expanded gradually as it went downstream.

A Study on the Integration process of School structure in East Germany after German Unification (독일통일 후 구동독 학제통합 과정 연구)

  • Kang, Gu Sup
    • Korean Journal of Comparative Education
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    • v.27 no.1
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    • pp.51-76
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    • 2017
  • This study aims to examine the integration process of educational system and school structure of the former East Germany into the Federal Republic of Germany following German unification. More specifically, the study focuses on drawing some policy suggestions and implications for achieving integration of South and North Korean educational system in a unified Korea. In fact, the school structure in the former East Germany had been integrated into West German educational system and school structure before and after official German unification by way of so called transitional process. The results of the study indicate that the integration process of school structure in the former East Germany into West German educational system was quite successful with stable management by means of various transitional measures and reaching an agreement between East and West Germany. Additionally, the study presents that local characteristics regarding school structure in the former East Germany were recognized and introduced in the integration process and they managed to handle the social change situation after German unification flexibly. However, it shows some shortcomings because it had been carried out in too short a period of time and the positive factors of school structure in the former East Germany had not been enough taken account into the integration process, along with the lack of inner comprehensive relevant infrastructure. Furthermore, the study points out that German case of school structure and its integration process after German unification has implications for specific ways Korea should pursue to achieve integration of South and North Korean educational system in a unified Korea. To be more specific, it suggests how we come up with plans and measures to establish integration of South and North Korean school structure in a stable way especially in terms of dealing with North Korean school structure and building an inner infrastructure.

A Study on the Rale of counselors as clients' Transitional object (내담자의 전이대상으로 상담자의 역할 연구)

  • Yoon, Seok-Min
    • Industry Promotion Research
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    • v.5 no.3
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    • pp.53-60
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    • 2020
  • This paper describes the role of counselors' transitional object for the therapeutic activation of clients who have lost the function of selfobject based on Heinz Kohut's Self theory. In this study, it was an opportunity to confirm that human beings need self-target throughout their lives. Next, referring to the process of metamorphic internalization, infants return to reality from a fantasy world, experiencing parental limitations due to optimal frustration through self-targeting. The role of a counselor as a transfer target shall ensure that the counsellor establishes an cohesive self-identity and uses the appropriate self-target. And they should empathize with the over-the-topism and flauntism of the physician, and the counselor should be the object of idealization, giving the interviewer the opportunity to be recognized and identified. The counselor may provide the best frustration for the counsellor during the consultation process. When the counselor acknowledges his mistake, the counselor looks at the counselor realistically and builds a healthy self to achieve transformative internalization. If you form an cohesive self to a physician through counseling, you can empathize with others and form a healthy human relationship. Then you can control your emotions and have a vision. And the patient realizes that he or she has no choice but to live by having a relationship with the right person throughout his or her life.

A Study on the Characteristics of the Component of Argumentation in the Process of Solving Scientific Argument Tasks among Elementary Students (과학적 맥락의 논의 과제 해결 과정에서 나타나는 초등학생들의 논의 과정 요소의 특성에 관한 연구)

  • Lee, Seok-Hee;Seo, Bong-Hee;Kim, Yong-Gwon
    • Journal of Korean Elementary Science Education
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    • v.26 no.1
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    • pp.76-86
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    • 2007
  • The purpose of this study is to investigate the characteristics of scientific argumentation and its development in the process of mutual discussion activities by elementary school students in the 5th grade. The results of this study can be summarized as below: First, students used diversity argumentation components for solving the given argumentation theme, however, most students used the assertion or the basis of a simple expression of their own thoughts as a high ratio, and components of a one directional explanatory argumentation process rather than components of a mutual communicative argumentation process. Second, an asymmetric group showed a high-use ratio of communicative argumentation components and achieved argumentation activities harmoniously between a symmetric group and an asymmetric group in organization of groups for solving argumentation themes. It was found that students in the transitional period showed the highest rate of participation within the discussion process. Moreover, they also showed the highest rate of development of discussion skills whilst in the process of using scientific problems. In conclusion, this phenomenon is caused by highlighting the mutual action between the teacher and the student rather than placing an emphasis on the mutual action among students during field instructions.

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A Study on the Metal Transfer Considering Fluid Flow in GMAW (가스 메탈 아크 용접에서 유체 유동을 고려한 금속 이행에 관한 연구)

  • 박기영;이세헌;엄기원
    • Journal of the Korean Society for Precision Engineering
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    • v.15 no.4
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    • pp.148-155
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    • 1998
  • It is commonly known that, in GMAW, the characteristics of metal transfer and the size of molten drop are highly dependent on the welding current. These changes in the characteristics of metal transfer has a considerable effect on the weld quality, and a lot of studies have been made on metal transfer modes for that reason. In this study, two cases were investigated; the one in which the metal transfer proceeds with gravitational force, surface tension, and no electromagnetic force, and the other in which the process has electromagnetic term in addition, where the current density in the fluid has been assumed to have Gaussian distribution on any given cross-section and it acts vertically. Using fluid flow analysis, this study has observed the whole process of the development and break-up of the molten drop, and it also showed that transitional processes, drop rate, and the drop size in each metal transfer mode can be estimated.

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A Study on the Presentation of Architectural Space in Painting of Louis I. Kahn (루이스 칸의 회화에 나타난 건축적 공간표현에 관한 연구)

  • Choi, Young-A;Kim, Joo-Sung;Lee, Kang-Up
    • Korean Institute of Interior Design Journal
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    • v.15 no.2 s.55
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    • pp.65-72
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    • 2006
  • The purpose of this study is to show the development process of space concept by studying on the Louis I. Kahn's painting as pre-architectural thinking. Generally the idea of an architect is represented with lots of mediums, and the architectural thinking is developed through the process. In his early days, he, as an architect, made many travel sketches of Europe. In these clays, painting was the most significant medium to him. Since 1950's, he also left lots of sketches affected by abstract painting in addition to travel sketches. The results of this study were as follows: He found the image of antiquity from his painting and he made this image into abstraction in the facade. And the image of ruins was translated the layered space which was the transitional space. And he presented 'marche' through the series of painting of various view point. The Concept of 'marche' was translated into the connections of repetitive mass in the architectural space.

Behavior of Global Bending Distortion of Hatch-cover in Container Carrier during Fabrication Process (컨테이너 운반선 해치-커버 제작시 전 굽힘 변형 거동에 관한 연구)

  • Lee, Dong-Ju;Kim, Gyung-Gyu;Shin, Sang-Beom
    • Journal of Welding and Joining
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    • v.28 no.4
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    • pp.41-48
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    • 2010
  • The purpose of this study is to establish the control method of the global bending distortion caused by fabrication process of hatch-cover in a container ship. In order to do it, the transitional behavior of global bending distortion in the deck of hatch-cover during fabrication process was measured by 3-dimensional measuring instrument. From the results, the principal factor controlling the global bending distortion was identified as the bending moment associated with the longitudinal shrinkage force and transverse shrinkage caused by welding and flame heating and the change of the centroid axis of hatch-cover in each fabrication process. Therefore, in this study, with the predictive equations of the longitudinal shrinkage force and transverse shrinkage caused by welding and flame heating and the simplified thermo elastic method, the predictive method for the global bending distortion was established and verified by comparing with the measured result. Based on the results, the amount of reverse bending distortion of main stiffeners was determined to prevent the global bending distortion of hatch-cover.

FINITE ELEMENT APPROACH TO INVESTIGATE THE INFLUENCE OF THE DESIGN CONFIGURATION OF THE ITI SOLID IMPLANT ON THE BONE STRESSES DURING THE OSSEOINTEGRATION PROCESS (유한요소해석을 통한 ITI Solid screw 임플랜트의 형상 특성이 골유착 단계에서 응력에 미치는 영향에 대한 연구)

  • Cha Sang-Bum;Lee Kyu-Bok;Jo Kwang-Hun
    • The Journal of Korean Academy of Prosthodontics
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    • v.44 no.2
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    • pp.217-228
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    • 2006
  • Statement of problem: Standard type of ITI solid implant model in the 6.2mm thick jaw bone was axisymmetrically modelled for finite element stress analyses. Purpose: Primary objective was to investigate the influences or the characteristic design configuration of the ITI solid implant model on the bone stress with the course of osseointegration process at the bone/implant interfaces. To simulate the characteristics of the osseointegration process, five different stages of the bone/implant interface model were implemented. As load conditions, vertical load of 50N was taken into consideration. Bone at the cervical region of implant was the areas of concern where the higher level of stress were likely to take place. Results: The results indicated that rather slightly different stress level could be obtained as a function of the osseointegration conditions. Conclusion: Under vertical load, the lower level of stress was observed at the cervical cortical bone in the initial and final stages of osseointegration. Relatively higher stress level, however, was observed during the transitional stages where the osseointegration at the cancellous bone interface were yet to fully develop.

Conservation Area Designation Method for Natural Environmental Management in a Rural Local Government (자치단체지역의 자연환경관리를 위한 보전지역 설정)

  • Lee, Gwan-Gyu;Sung, Hyun-Chan;Choi, Jaeyong
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.10 no.5
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    • pp.1-9
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    • 2007
  • Local government with abundant natural resources should consider the nature conservation oriented planning process for the sustainable development. With this regard, the aim of this study is to provide a substantial methodology to support the decision-making process to designate the conservation areas. The objectives of the proposed methodology is to conserve natural resources in the local government's territory through quantitatively assessing the values of the natural resources based on various ecological factors such as topography, flora and fauna. In order to test the usability of the method, Gangneung City in Kangwon-Do is selected considering the latest data availability. Based on the assessment process land use of the subjected city could be categorized into 4 levels of conservative area, conservative level 1 area, conservative level 2 area, and conservative level 3 area. Among them, conservative area and conservative level 1 area could be combined as natural resources conservation area and the others could be regarded as buffer and transitional area. Especially conservation area is surrounded by conservation level 2 area. Conclusively, the GIS methods adopted in this could be the efficient illustrative tool to assess the local natural resource values with the central government established nature-environmental information systems.

A Study on the Prediction of Welding Distortion of Vacuum Vessel during Fabrication Process (진공 용기 제작시 공정별 변형 예측에 관한 연구)

  • Lee, Dong-Ju;Kim, Ha-Geun;Shin, Sang-Beom
    • Proceedings of the KWS Conference
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    • 2009.11a
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    • pp.96-96
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    • 2009
  • The purpose of this study is to clarify the transitional behavior and main factor of excessive welding distortion caused by fabrication process of STS 304 vacuum vessel having double curvature for the efficient quality control of vacuum vessel. In order to do it, the predictive equations of the welding distortion in simple weldment of vacuum vessel were established by conventional finite element analysis. And the principal factor controlling the welding distortion was identified by evaluating the welding distortion of vacuum vessel in each fabrication process with FEA and simplified thermo elastic method. Based on the results, the principal factors of distortion of vacuum vessel were clarified as angular distortion and transverse shrinkage which are a source of excessive out-of plane distortion in the double curved vacuum vessel. It was expected that the FE analysis results of this study could contribute to establish the proper control method of welding distortion for double curved vacuum vessel.

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